We’re told that hundreds of fish died at Sloan’s Lake because the oxygen levels in the lake became dangerously low. Why did the oxygen levels become so low in the lake? Well, we get a familiar explanation from: “The experts [who] said they think the decreased oxygen levels occurred when algae began dying off as nighttime temperatures fell below 40 degrees.
“The dead algae ended up at the bottom of the shallow lake where it was consumed by bacteria and microbes that essentially sucked the oxygen from the water, said Ellen Dumm, Denver’s environmental health communications director.” (Rocky Mtn News, Hector Gutierrez)
Hmmm… “…dead algae…consumed by bacteria and microbes…that essentially sucked the oxygen from the water…” Sound familiar? An earlier entry, “Ducks Dying…,” includes the following:
Historically speaking, it was not so very long ago that lakes, rivers and coastal waters were clean and supported a balanced aquatic plant and animal life. As rivers and lakes started to receive organic pollution from industry, sewers, septic systems, and present -day agricultural and livestock-raising practices, these organics decomposed in the water, consuming the oxygen dissolved in it–oxygen crucial for fish and other aquatic animals. This process is known as primary pollution.
Concomitant with the primary pollution, algae and other “out -of- balance” plant species start to grow as the result of being fertilized by the surge of nutrients from the above-mentioned sources. These fertilized plants, in turn, die and decompose, further robbing the water of its naturally dissolved oxygen. This phase is called secondary pollution (Diagram A), or “eutrophication”, and is considerably more damaging to the oxygen level than primary pollution.
Second–if only to remind us of the additional scourge brought on by this pollution–we need to understand what “Avian Botulism is.” From this site, comes the following:
Avian botulism is a paralytic disease caused by ingestion of a toxin produced by the bacteria, Clostridium botulinum. This bacteria is widespread in soil and requires warm temperatures, a protein source and an anaerobic (no oxygen) environment in order to become active and produce toxin. Decomposing vegetation and invertebrates combined with warm temperatures can provide ideal conditions for the botulism bacteria to activate and produce toxin. There are several types of toxin produced by strains of this bacteria; birds are most commonly affected by type C and to a lesser extent type E.
Okay. So, it appears–after the initial entry of “Denver’s Parks – A Killing Field“–the deaths of hundreds of ducks at Denver park’s lakes, was exacerbated by “graywater” effluent being pumped into those lakes.
Back to Sloan’s.
A story appearing in the October 19th edition of the Rocky Mtn. News notes: “On Thursday [October 11th? 18th?] the Denver Parks and Recreation Department worked with Rocky Mountain Ditch to open flood inlets to allow more fresh water to enter [Sloan’s] lake. Environmental and parks officials said they believe hundreds of fish swam toward the western shore [of Sloan’s Lake] because the lake’s oxygen levels had fallen considerably, killing many of the fish.”
The “…western shore…” of Sloan’s is where this supposed “…fresh water…” enters the lake via what is known as the Rocky Mountain Ditch.
Comes a post from Toxic Sleuth with regard to Rocky Mountain Ditch, the headwaters of which are within the Coors Brewing operation in Golden. The post reads, in part: “Also curious is that none of the news agencies in Denver have reported anything about the fact that the sole source of the water to Sloan’s Lake – the Rocky Mountain Ditch – is operated by a wholly-owned subsidiary of the Coors Company. The ditch originates on the Coors complex between two of its industrial buildings in Golden. In years not so long ago, even an inexperienced reporter would have inquired of Coors or state officials if they might have had a toxic release that meandered down their ditch to enter the lake at precisely the point were all the fish were dying. The question certainly should be asked, since Coors’ illegal toxic release incidents have become commonplace over the last couple of decades, killing hundreds, even thousands of fish downstream from their industrial operations.”
Okay. Curiously, Denver’s web site, DenverGov , describes the Rocky Mountain Ditch as:
The Rocky Mountain Ditch and Lake Park a part of more than 100 year-old ditch watering system, meandering many miles from Golden through Denver, and ending at the Rocky Mountain Lake Park near I-70. The ditch provided water to a mainly agricultural area in the past, but over time, its users have dwindled mostly to farming in Golden. The City of Denver is considering acquiring the ditch to provide for its maintenance as it affects the homes of many citizens throughout Denver.
The ditch system runs both above and below the ground from Golden feeding Rocky Mountain Lake Park. This lake is maintained by Denver’s Parks and Recreation department, who are working on improving the lake water quality and fish wildlife, one important phase of this expansive system project. [This information on the city’s site is dated, 2001, and emphasizes a remediation project completed on or about October, 2001.)
The city’s information with regard to the Rocky Mountain Ditch mentions nothing about it feeding Sloan’s Lake and, also curiously, places the ditch’s location–within the city limits–from 38th Avenue north. Sloan’s Lake is, of course, significantly south of 38th. However, Berkeley Lake is within the city-noted boundaries of the Rocky Mountain Ditch. Does Rocky Mountain Lake feed Berkeley Lake? I don’t know. Another question: Has this so-called meandering Rocky Mountain Ditch been modified, re-channeled over the years, in such a way that only Sloan’s Lake receives the influx from the headwaters within the Coors complex, and Rocky Mountain Lake–because of said modifications or re-channeling–does not? Again, I don’t know.
The point, of course, is why didn’t the fish in Berkeley and Rocky Mountain Lake die of suffocation from the effects of low overnight temperatures killing algae [as the “experts” assert] as did the fish in Sloan’s Lake? Again, I don’t know.
What I do know is that lake management within the City and County of Denver sucks. I also know that Sarah and I visited Sloan’s Lake last week and found dead fish within the inlet where, supposedly, “fresh” water was being infused into the lake. Witness: